Mounting structure for sensor attached to heat exchanger

ABSTRACT

A mounting structure is provided, for a sensor which is attached to a heat exchanger. An evaporator that is utilized in a vehicular air conditioning apparatus is equipped with a detection sensor, which is capable of detecting the surface temperature of the evaporator. In the detection sensor, a main body portion thereof on which the detector is provided is inserted between fins of the evaporator. After a cable is made to extend to a cable guide disposed on a side portion of a casing, the cable is retained by the cable guide.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2009-215176 filed on Sep. 17, 2009, of which the contents are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mounting structure for a sensor, which is attached, for example, to a heat exchanger that is disposed in a vehicular air conditioning apparatus, and which is provided for the purpose of detecting the temperature of air that has passed through the heat exchanger.

2. Description of the Related Art

Heretofore, in a vehicular air conditioning apparatus installed in a vehicle such as an automobile or the like, air is drawn into a housing by a fan, and after the air, which has been cooled by an evaporator (heat exchanger) that serves as a cooling means, and air, which as been heated by a heater core that serves as a heating means, are mixed together at a predetermined mixing ratio inside the housing, the air is selectively blown out from blowout ports disposed in the vehicle compartment, whereby the temperature and humidity inside the vehicle compartment can be adjusted.

As shown in FIG. 6, on an evaporator 1, which is disclosed in Japanese Laid-Open Patent Publication No. 2006-017406, there is attached a temperature sensor 2 on a side thereof forming a downstream side of air that passes through the evaporator 1, for detecting the surface temperature of the evaporator 1. Additionally, based on the temperature that is detected by the temperature sensor 2, control of air conditioning inside the vehicle compartment of the vehicle is carried out.

The temperature sensor 2 is constituted from a housing 4 having a sensor portion 3, and a cable 5 that is connected to a side surface of the housing 4. Through insertion of the sensor portion 3 between fins 6 that make up the evaporator 1, the housing 4 is fixedly attached to a side surface of the evaporator 1. Further, the cable 5 is connected electrically with respect to a controller or the like installed in the vehicle, and together therewith, the path of the cable 5 is restricted by plural clamp members 7 a, 7 b, which are attached to the side surface of the evaporator 1, whereby the cable 5 is guided to a desired location.

However, using the above-described conventional technique, when the temperature sensor 2 is mounted, the plural clamp members 7 a, 7 b must be installed on the evaporator 1 beforehand in order to arrange the cable 5 thereof along a desired path, which is cumbersome and increases the number of parts, together with increasing the number of assembly steps required to assemble the apparatus. Further, because the clamp members 7 a, 7 b are affixed by insertion thereof into the fins 6, for example, damage to the fins 6 can result, leading to a concern that performance of the heat exchanger will become degraded.

SUMMARY OF THE INVENTION

A general object of the present invention is to provide a mounting structure for a sensor that is attached to a heat exchanger, which is capable of reducing the number of parts and assembly steps when the sensor is mounted to the air conditioning apparatus.

The present invention is characterized by a mounting structure for a sensor attached to a heat exchanger in a vehicular air conditioning apparatus installed in a vehicle, the heat exchanger cooling or heating air supplied to a passage of a casing for blowing the air at a predetermined temperature into a vehicle compartment, and the sensor carrying out temperature detection of the heat exchanger.

The sensor comprises a detector attached with respect to the heat exchanger for carrying out detection of temperature of the heat exchanger, and a cable connected to the detector, wherein a guide member is formed in the casing, and the guide member restricts a path of the cable and is capable of retaining the cable.

According to the present invention, in the heat exchanger, which is utilized in a vehicular air conditioner installed in the vehicle, a sensor is installed that detects the temperature of the heat exchanger. A cable, which is connected to the detector of the sensor, is restricted to a desired path and is retained by the guide member, which is formed in the casing of the vehicular air conditioner.

Accordingly, a cumbersome operation like that of the conventional sensor mounting structure, of attaching each of plural clamp members with respect to the heat exchanger in order to restrict the path of the cable, is no longer necessary. Along therewith, when the sensor is installed, the number of assembly steps can be reduced, together with decreasing the number of parts and associated costs for the mounting structure.

The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exterior perspective view showing a vehicular air conditioning apparatus having a heat exchanger, to which a mounting structure for a sensor according to an embodiment of the present invention is applied;

FIG. 2 is an enlarged perspective view showing the vicinity of an opening of a first divided casing in the vehicular air conditioning apparatus of FIG. 1;

FIG. 3 is an enlarged front view of the vicinity of a cable guide shown in FIG. 2;

FIG. 4 is a cross sectional view taken along line IV-IV of FIG. 2;

FIG. 5A is an enlarged plan view showing a condition in which a detection sensor is installed on an evaporator, and FIG. 5B is an enlarged side view of FIG. 5A; and

FIG. 6 is a front view of a heat exchanger on which a sensor is attached according to a conventional technique.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, reference numeral 10 indicates a vehicular air conditioning apparatus having a heat exchanger therein on which a sensor according to an embodiment of the present invention is installed.

As shown in FIGS. 1 and 2, the vehicular air conditioning apparatus 10 includes a casing 12 made up of respective air passages, an evaporator 14 (heat exchanger) for cooling air arranged in the interior of the casing 12, a heater core (not shown) for heating air, and a duct 18 installed at an opening 16 of the casing 12, which guides air supplied from a fan into the interior of the casing 12. Further, in the interior of the casing 12, there are disposed an air mixing door (not shown) through which heat exchange is performed on the air guided into the casing 12 by means of the evaporator 14 and the heater core, and for creating mixed air by mixing at a predetermined mixing ratio the cool air and the heated air having been adjusted in temperature, and a plurality of blowout port doors for selectively supplying the mixed air into the vehicle compartment from each of the opened blowout ports.

The casing 12 is constituted from first and second roughly symmetrical divided casings 20, 22. The duct 18 is installed on the opening 16, which opens on a side portion of the first divided casing (casing) 20, and together therewith, the evaporator 14 is accommodated through the opening 16 from the exterior of the casing 12 to the interior thereof.

As shown in FIGS. 2 through 4, there is disposed in the first divided casing 20 a cable guide (guide member) 24 for guiding a cable 50 of the detection sensor (sensor) 46 referred to below at one side of the opening 16. The cable guide 24, for example, is formed from a resin material similar to that of the casing 12 itself, which is disposed on an end surface of the opening 16 on which the duct 18 is installed. Further, the cable guide 24 is formed so as to project in a substantially horizontal direction oriented toward the center of the opening 16.

Further, as shown in FIGS. 2 through 4, the cable guide 24 is made up from a planar shaped base portion 26, which is joined to the end of the opening 16 and projects toward a side of the opening 16, and a pair of first and second guide walls (wall portions) 28, 30, which project with respect to the base portion 26 toward a direction separating away from the opening 16. Additionally, the first and second guide walls 28, 30 are upstanding perpendicularly with respect to the base portion 26, and extend in a vertical direction perpendicular to a direction in which the base portion 26 extends.

Stated otherwise, the first and second guide walls 28, 30 are upstanding toward an exterior side (side of the opening 16) of the first divided casing 20, and the first and second guide walls 28, 30 are disposed in parallel while being separated a predetermined distance from each other on the base portion 26. More specifically, the cable guide 24 is formed to have a U-shape in cross section from the base portion 26 and the pair of first and second guide walls 28, 30. Further, the height of the first and second guide walls 28, 30 from the inner wall surface of the base portion 26 is set to be substantially the same or somewhat larger than the diameter of the cable 50.

The first guide wall 28 is disposed more toward the central side of the opening 16 than the second guide wall 30. A hook member (retainer) 32 capable of retaining the cable 50 of the detection sensor 46, to be described later, is included on the first guide wall 28.

The hook member 32 is disposed at an end of the first guide wall 28 at a position separated maximally from the base portion 26. The hook member 32 projects from the end toward the side of the second guide wall 30, and is formed so as to extend in a longitudinal direction of the first guide wall 28. Additionally, when the cable 50 is retained by the cable guide 24, the hook member 32 is held against and holds the outer circumferential surface of the cable 50, in a state in which the cable 50 abuts against inner wall surfaces of the base portion 26 and the first guide wall 28.

Stated otherwise, the cable 50 is placed in a state such that roughly half of the outer circumferential surface is retained by the base portion 26, the first guide wall 28 and the hook member 32.

Further, when the cable 50 is retained by the hook member 32, the cable 50 is retained so as to be displaceable along a longitudinal direction of the cable 50, but wherein displacement of the cable 50 in a direction to separate away from the cable guide 24, i.e., displacement in the radial direction of the cable 50, is restricted.

On the other hand, the cable guide 24 has a flexible elasticity about a fulcrum where the cable guide 24 is joined with respect to the casing 12. More specifically, the cable guide 24 is formed such that the base portion 26 thereof, which is joined to the casing 12, has a plate thickness (thickness dimension) that enables flexibility, so that the cable guide 24 is tiltable with respect to the casing 12 by a predetermined angle to the horizontal direction.

Furthermore, in the first divided casing 20, a cable hole 34 (see FIG. 1) opens at a position upwardly of the cable guide 24, and the cable 50 of the later-described detection sensor 46 passes through the cable hole 34 from the interior to the exterior of the first divided casing 20.

As shown in FIGS. 1, 5A and 5B, the evaporator 14 comprises a plurality of tubes 36 through which a coolant flows, fins 38 which are bent in a wavelike form in a serpentine pattern between the tubes 36, and a pair of tanks 40 a, 40 b disposed at opposite ends of the tubes and in which the coolant is collected. In addition, on one of the tanks 40 a, the coolant is introduced from the exterior through a supply pipe 42, and after the coolant has circulated in the interior of the evaporator 14 through the tubes 36 whereupon heat exchange is performed thereby, the coolant is directed out to the exterior from a discharge pipe 44, which is connected again to the tank 40 a.

More specifically, on the evaporator 14, the plural tubes 36 and fins 38 are separated mutually by equal distances and are arranged in parallel in the widthwise direction, and the tanks 40 a, 40 b, which are disposed at opposite ends of the tubes 36 and the fins 38 are formed in a boxlike shape, arranged at upper and lower portions of the evaporator 14 (see FIG. 1).

Further, the detection sensor 46 is disposed on a side surface of the evaporator 14 in order to detect the surface temperature of the evaporator 14. The detection sensor 46 includes a main body portion 48 which is mounted on the evaporator 14, the cable 50 connected to the main body portion 48, and a connector 52 connected to another end of the cable 50. The detection sensor 46 is disposed on a side surface of the evaporator 14, which forms a downstream side thereof when air passes through the evaporator 14 and heat exchange is performed thereon.

A detector 56 (see FIGS. 5A and 5B) projects on the main body portion 48 from a lower surface thereof. The detector 56 is formed, for example, from a thermistor. Further, the cable 50, which is connected electrically to the detector 56 in the interior of the main body portion 48, is connected to a side of the main body portion 48.

In addition, the detector 56 of the detection sensor 46, which has a projecting columnar shape, is supported on a side surface of the evaporator 14 by insertion thereof between the fins 38 on the evaporator 14. The main body portion 48 including the detector 56 is affixed with respect to the evaporator 14. The main body portion 48 of the detection sensor 46 is mounted so as to be roughly parallel to the tanks 40 a, 40 b and perpendicular to the direction of extension of the tubes 36.

On the other hand, the cable 50 is formed with a predetermined length, one end thereof being connected to the main body portion 48, and the connector 52, which is connected to connection terminals of a non-illustrated controller, being connected to the other end of the cable 50. In addition, in a condition where the detection sensor 46 is mounted on a side surface of the evaporator 14, the cable 50 extends in a straight line alongside the evaporator 14, i.e., in a substantially horizontal direction, and after insertion through the cable guide 24 formed in the first divided casing 20, the cable 50 is directed upwardly.

Further, the cable 50, after having been guided upward by the cable guide 24, passes through the cable hole 34 formed in the first divided casing 20 and is inserted therethrough to the outside. At this time, the cable 50 is fixed in place by being sandwiched and gripped between the opening 16 of the first divided casing 20 and the duct 18 that is installed on the opening 16.

The vehicular air conditioning apparatus 10, having a heat exchanger on which the sensor according to the embodiment of the present invention is mounted, is constructed basically as described above. Next, a method of assembling the detection sensor 46 and the evaporator 14 shall briefly be described.

Initially, in a state in which the opening 16 of the first divided casing 20 is opened, when the evaporator 14 is arranged inside the casing 12, the detection sensor 46 is mounted on a side surface of the evaporator 14 that forms the downstream side thereof. More specifically, the detection sensor 46 is moved to a region on the evaporator 14 where it is desired to detect the surface temperature, and the detector 56 thereof is inserted between the fins 38 of the evaporator 14 and fixed there in place.

Next, from the opening 16, the evaporator 14 together with the detection sensor 46 is inserted into and housed in the interior of the first divided casing 20, and the cable 50 of the detection sensor 46 is made to extend along one surface side of the evaporator 14 so as to be roughly parallel with the tanks 40 a, 40 b of the evaporator 14. Additionally, the cable 50, after having been extended to reach the cable guide 24 of the first divided casing 20, is inserted therethrough to the outer side of the cable guide 24 that faces toward the exterior of the first divided casing 20. Moreover, the evaporator 14 is fixed at a predetermined position in the interior of the casing 12, which is made up from the first and second divided casings 20, 22.

At this time, the cable 50 is inserted so as to abut against the first guide wall 28 and the base portion 26 that make up the cable guide 24, and further is inserted between the hook member 32 and the base portion 26 of the cable guide 24. Consequently, the cable 50 is retained reliably and securely in the cable guide 24 via the base portion 26, the first guide wall 28, and the hook member 32.

In addition, after the path of the cable 50 is changed and bent upward at a right angle by the cable guide 24, the cable 50 extends upwardly and is drawn out to the exterior from the cable hole 34 formed in the first divided casing 20.

Lastly, the duct 18 is installed on the opening 16 of the first divided casing 20, and by fitting thereof into the opening 16, a portion of the cable 50 becomes gripped and fixed between the opening 16 and the duct 18. At this time, while being guided by the cable guide 24, the cable 50 is pulled out toward the other end side to which the connector 52 is connected. In a tensioned state in which a certain amount of tension is applied to the cable 50, the cable 50 is fixed in place by the duct 18. Then, deflection of the cable 50, etc., does not occur, and thus an appropriate condition is obtained.

Then, the connector 52, which is connected to the cable 50, for example, is connected to connection terminals of a controller that is installed in the vehicle. Accordingly, the surface temperature of the evaporator 14, which is detected by the detection sensor 46, is output to the controller as detection signals via the cable 50 and the connector 52.

In the foregoing manner, with the present embodiment, the detection sensor 46 is mounted with respect to the evaporator 14, which is used in the vehicular air conditioning apparatus 10, such that when the surface temperature of the evaporator 14 is detected, the cable guide 24 is formed beforehand in the vicinity of the opening 16 of the first divided casing 20 that makes up the vehicular air conditioning apparatus 10. Owing thereto, when the detection sensor 46 is installed on the evaporator 14, the cable 50 is guided suitably by the cable guide 24, and can be directed to the exterior of the casing 12 along a predetermined path. As a result, there is no need for a plurality of clamp members to restrict the path of the cable 50 of the detection sensor 46, as was necessary in the assembly structure of the conventional art. Along therewith, the number of assembly steps can be reduced, together with decreasing the number of parts and associated costs for the detection sensor 46.

Further, even in a case where tensile forces are applied to the cable 50 that is retained by the cable guide 24, for example, by variances in the attachment position of the detection sensor 46 or by pulling of the cable 50 during the assembly operation, because the cable guide 24 is joined in a flexible manner with respect to an end surface of the opening 16 in the first divided casing 20, such tensile forces can suitably be absorbed, and undesirable movements in the position of the detection sensor 46 can be avoided. Further, faulty operation of the detector 56 or the like, which is a concern in the case that tension is applied to the detector 56 via the cable 50, can be avoided.

Furthermore, the cable guide 24 includes the pair of first and second guide walls 28, 30, and since the cable 50 is retained between the first and second guide walls 28, 30, the cable 50 is suitably held by the pair of first and second guide walls 28, 30 and separation of the cable 50 from the cable guide 24 can be prevented.

Still further, on the aforementioned first guide wall 28, since a hook member 32 is provided, which is cable of retaining the cable 50 under a condition in which the cable 50 abuts against inner wall surfaces of the base portion 26 and the first guide wall 28, the cable 50 can reliably be retained by the cable guide 24 including the first guide wall 28. Moreover, because the hook member 32 retains the cable 50 so as to be displaceable in the longitudinal direction, even in the case that the cable 50 is displaced along the longitudinal direction by variances in the installation position of the detection sensor 46 or the like, the cable 50 can appropriately be displaced freely under a condition in which the cable 50 is retained by the hook member 32.

More specifically, the hook member 32, which is provided on the first guide wall 28, allows displacement of the cable 50 along the longitudinal direction, while conversely, the hook member 32 restricts displacement of the cable 50 in a direction whereby the cable 50 would separate away from the cable guide 24, i.e., in the radial direction of the cable 50.

Still further, since it is not necessary to install a plurality of clamp members, as used in the sensor mounting structure of the conventional art, with respect to the fins 38 of the evaporator 14, damage to the fins 38, which is a problem when such clamp members are installed, can be avoided.

Further, because the cable 50 of the detection sensor 46 is firmly retained by the cable guide 24, the cable 50 is not subjected to bending in the vicinity of the side surface of the evaporator 14, and thus the cable 50 coming into contact with the air mixing door (not shown), which would be of concern if the cable 50 were to become bent, can be avoided.

The mounting structure for a sensor, which is attached to a heat exchanger according to the present invention, is not limited to the aforementioned embodiment. It is a matter of course that various changes and modifications may be adopted without departing from the scope and essence of the invention as set forth in the appended claims. 

1. A mounting structure for a sensor attached to a heat exchanger in a vehicular air conditioning apparatus installed in a vehicle, the heat exchanger cooling or heating air supplied to a passage of a casing for blowing the air at a predetermined temperature into a vehicle compartment, and the sensor carrying out temperature detection of the heat exchanger, the sensor comprising a detector attached with respect to the heat exchanger for carrying out detection of temperature of the heat exchanger, and a cable connected to the detector, wherein a guide member is formed in the casing, the guide member restricts a path of the cable and is capable of retaining the cable.
 2. The mounting structure according to claim 1, the guide member further comprising: a base portion joined to the casing; and a wall portion which is upstanding with respect to the base portion, wherein, on the wall portion, a retainer is provided, which is capable of retaining the cable together with the base portion and the wall portion.
 3. The mounting structure according to claim 1, wherein the guide member is flexibly disposed with respect to the casing.
 4. The mounting structure according to claim 1, wherein the guide member is disposed to one side of the heat exchanger, and is formed substantially parallel to a vertical direction of the casing.
 5. The mounting structure according to claim 1, wherein the guide member is disposed in an opening that opens on a side portion of the casing for accommodating the heat exchanger in the interior of the casing.
 6. The mounting structure according to claim 2, wherein the retainer retains the cable in a displaceable manner along an axial direction of the cable, while restricting displacement in a radial direction of the cable.
 7. The mounting structure according to claim 2, wherein the wall portion comprises a pair of wall portions disposed with respect to the base portion, the retainer being disposed on one of the wall portions and distanced from the base portion.
 8. The mounting structure according to claim 1, wherein the guide member is formed with a U-shape in cross section from a base portion joined to the casing and wall portions which are upstanding with respect to the base portion. 